Whole blood is made up of various cellular and non-cellular components such as red cells, white cells and platelets suspended in its liquid component, plasma. Whole blood may be separated into its constituent components (cellular, liquid or other), and the separated component(s) may be administered to a patient in need of that particular component or components.
The administration of blood and/or blood components is common in the treatment of patients suffering from disease. Rather than infuse whole blood, individual components may be administered to the patient(s) as their needs require. For example, administration (infusion) of platelets may often be prescribed for cancer patients whose ability to make platelets has been compromised by chemotherapy. Infusion of white blood cells (i.e., mononuclear cells) after the cells have undergone some additional processing or treatment may also be prescribed for therapeutic reasons, including treatment of diseases that specifically involve the white blood cells. Thus, it may be desirable to separate and collect the desired blood component from whole blood and then treat the patient with the specific blood component. The remaining components may be returned to the patient or retained for other uses.
There are several diseases or disorders which are believed to primarily involve mononuclear cells, such as cutaneous T-cell lymphoma, organ allograft rejection after transplantation and autoimmune diseases such as rheumatoid arthritis and systemic sclerosis, among others.
Cutaneous T-cell lymphoma (CTCL) is a term that is used to describe a wide variety of disorders. Generally, CTCL is a type of cancer of the immune system where T-cells (a type of mononuclear cell) mutate or grow in an uncontrolled way, migrate to the skin and form itchy, scaly plaques or patches. More advanced stages of the disease also affect the lymph nodes. Therapeutic treatment options for CTCL have previously been limited. While chemotherapy has been utilized, this particular form of treatment also has many associated undesirable side effects, such as lowered resistance to infection, bleeding, bruising, nausea, infertility and hair loss, just to name a few.
Organ allograft rejection may be characterized as the rejection of tissues that are foreign to a host, including transplanted cardiac tissue as well as lung, liver and renal transplants. Immunosuppression drug therapy following transplantation is common. However, there are potential drawbacks including reoccurring infection due to the compromised competence of the immune system caused by this type of therapy.
Similarly, graft versus host disease (GVHD) is a complication that can occur after a stem cell or bone marrow transplant in which the newly transplanted material attacks the transplant recipient's body. The differences between the donor's cells and recipient's tissues often cause T-cells from the donor to recognize the recipient's body tissues as foreign, thereby causing the newly transplanted cells to attack the recipient. GVHD may complicate stem cell or bone marrow transplantation, thereby potentially limiting these life-saving therapies. Therefore, after a transplant, the recipient is usually administered a drug that suppresses the immune system, which helps reduce the chances or severity of GVHD.
Autoimmune diseases, including rheumatoid arthritis (RA) and progressive systemic sclerosis (PSS), can be characterized by an overactive immune system which mistakes the body's own tissues as being a foreign substance. As a result, the body makes autoantibodies that attack normal cells and tissues. At the same time, regulatory T-cells, which normally function to regulate the immune system and suppress excessive reactions or autoimmunity, fail in this capacity. This may lead to among other things, joint destruction in RA and inflammation of the connective tissue in PSS.